Toto/Korky valve issues (with new cap)

Discussion in 'Toilet Forum discussions' started by itsr-ent, Sep 10, 2018.

  1. itsr-ent

    itsr-ent Member

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    I have a Toto Eco Drake with the Korky style fill valve. Toilet was purchased/installed in 2015. About a year after installation, the fill valve was hissing. I tested to see if water was leaking into the bowl, didn't find anything, and replaced the R528 cap and cleaned the green filter and float chamber valve. That solved the issue, but my water pressure was around 120psi and I figured that was one of the reasons for early failure.

    I installed a PRV and reduced water pressure to 72psi. I know that's still sometimes considered high (though code is <80psi), but I wanted to minimize the change from being used to 120psi.

    A week ago I noticed the fill valve randomly running (not after a recent flush). Replaced the cap with a new one, but that didn't fix it. I tested and found the tank water level dropping and a VERY slight trickle of water down the sides of the bowl. Replaced the flapper with a Korky 2023BP set up correctly (flapper setting and chain length). That solved the issues...until...

    A week later (yesterday and today), the fill valve isn't turning off completely after most flushes. Water isn't leaving the tank, so the new flapper seems fine. I replaced the cap AGAIN three times (two brand new ones, and the one I put in there a week ago when it was really a flapper issue with no luck.

    I took the fill valve apart again and cleaned it well. No change. I ran the fill valve without the green cover on it and when it mostly turns off, water is spraying from the little hole on top of the R528 cap. If I ever so slightly lift the float or push down on the float arm, it stops. But as soon as I release, it starts hissing and spraying a bit of water. If you leave it for a few minutes, sometimes it shuts off completely and stays off.

    I took it apart AGAIN and looked at the float. I'm thinking maybe the little rubber pad is worn out? It has a decent little dent (see picture below). Can this be replaced? I have a Toto/Korky 528GT fill valve that I bought as a spare, but I don't really want to swap out the OEM fill valve if I don't have to. I read that the "only wear item" in these valves is the cap, so I'm confused why I'm having so many issues!

    Thanks in advance for any help/tips!

    IMG_0488.jpg
     
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    When you installed the PRV, did you also install an expansion tank? WIthout one, your water pressure could rise to 150psi, unless something else leaks to bleed it off while the water heater is running. If everything in the home is tight, the T&P on the WH will leak to relieve the pressure. That high pressure will quickly wear on the seal in the toilet fill valve.
     
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  4. wjcandee

    wjcandee Wise One

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    Observe the operation of the valve.

    When does it shut off? Does it shut off before the water rises to the level of the rectangular hole in the side of the float chamber? That hole is where the water should enter the float chamber to raise the float and shut off the valve. When it goes in there, it rushes in and shuts the valve off completely and with enough water to keep it shut off.

    There is a little hole on the bottom of the float chamber, with a little valve in it. You can find it by running your finger underneath the float chamber. When it operates properly, water can't get in there as the tank refills (causing the float not to rise until the water rushes in through the side hole), but once the tank water level drops after you flush, the little valve allows water to flow OUT of the float chamber and thus releases the float and opens the valve. If, on the other hand, the little valve at the bottom of the float chamber is clogged/jammed, it can remain open and water can enter there and push up on the float. It will cause the float to shut off the valve prematurely, which usually leads to stuttering or attempts by the valve to fill a little more.

    If the cap isn't the problem (and it doesn't appear to be here), then I would suspect that little one-way valve at the bottom of the float chamber. Usually just operating it with your finger and/or using a q-tip in the area of it after removing the float will get it back in business. The key to whether that's the issue is WHEN the valve shuts off when you operate it. If it shuts off initially before the water level reaches the rectangular hole in the side of the float chamber, that is almost certainly your problem.

    The pilot seat that you took a picture of looks serviceable (although it's a little hard to tell if it's flush from the angle of the photo), but the dimple indentation made on it by the little plastic rod at the top of the R528 cap seems a little off of where it should be. It normally is more-centered. This suggests that maybe you haven't been clicking the float back in properly. If it's not in there properly, then it doesn't have the same leverage over the rubber seal that it should have. Just a thought. Have a look at this video, taking special note of how they reinstall the float at 1:49, and see if that doesn't fix the problem.





    Let us know if neither suggestion does the trick.
     
  5. itsr-ent

    itsr-ent Member

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    Yes, I installed an expansion tank too. It's set for 1-2 psi above what I have the PRV set to. I also have a gauge installed after the PRV to monitor the pressure. After the install I made sure to check the gauge after a shower when all fixtures are closed and the water heater has run for a while. The pressure didn't rise, so I assume it's working. It's also the type where you can see if it fails when the cap turns red, and it looks good (only a few years old).
     
  6. itsr-ent

    itsr-ent Member

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    Thanks for the detailed explanation and video! It does seem to be functioning as designed...it doesn't attempt to turn off until the water rushes into the rectangular hole in the side and the water level is at the top of that hole. The little hole/ball at the bottom of the float chamber is in good shape. It wasn't dirty or stuck to begin with, but I did make sure to wipe it well and can roll the little ball around with my finger easily. It looks/feels the same as on the new spare valve I have.

    The pilot seat rubber that I took a picture of is flat/flush. I am 100% sure I am installing the float correctly per the video (it doesn't seem like you could actually click it in incorrectly...maybe if you miss one of the sides?). I pulled the float out of my spare 528GT valve to compare and the rubber seat on that one was darker red and much softer/more rubbery. I compared the floats and since they looked identical otherwise, I put the new float in my Toto OEM valve. That seems to have fixed the issue...the issue was happening with every flush and now hasn't happened in 10+ flushes and was also good after sitting overnight.

    I think this was a combination of two issues -- the rubber seat on the float was getting a bit worn/hard AND I noticed that when re-attaching the fill tube, it's easy to accidentally spin the cap a little counter clockwise. This probably changes the position of the little hole slightly and it wasn't hitting in the exact spot where the indentation had formed. Now that it's working, I don't want to put the old float back in and make sure the cap is tight clockwise to test that...
     
  7. wjcandee

    wjcandee Wise One

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    Thanks for the explanation and report on what you did! Very interesting, and will become part of our accumulated wisdom.

    Yeah, the usual mistake on reinstalling the float is that one doesn't push it all the way forward or gets one side to click and not the other, so that it binds or doesn't press down on the plunger correctly. It's not an easy mistake to make, but it happens.

    I agree that now that it ain't broke, to leave it alone!

    I myself would of course probably be unable to resist trying to experiment, which in my experience often leads to a non-optimal result. Dang it -- I should have just left it, etc. That's how I ended up with a Korky 528PRO in my weird old toilet in the City. Everybody said that it shouldn't work in that toilet, so I initially replaced the valve with the "proper" one when the old one broke on a holiday weekend. Got it working fine again. Then I got to thinking...I could just try the 528PRO. What could go wrong? Ahem. Five trips to the 24 hour hardware store in the middle of the night to get new hoses when the old one gave way, tape to fix the leak in the wall valve, a different wrench once something went sideways, etc... Of course, now that the 528PRO is in and I have proven it is an appropriate solution, yippee! But it wasn't the five-minute swap for the perfectly-fine "correct" valve that I expected it to be. The perils of experimenting!
     
  8. itsr-ent

    itsr-ent Member

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    I wish we had a 24hr hardware store!
     
  9. itsr-ent

    itsr-ent Member

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    Had a minute to check out the old float and thought this was worth mentioning. The little rubber seat/disc pops out easily and it looks like you could put it in backwards to use the other side if anyone has a similar issue. They don't sell a replacement rubber seat, do they?
     
  10. wjcandee

    wjcandee Wise One

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    Yeah, I stumbled upon The Nuthouse on East 29th Street in Manhattan years ago, and have needed its services more often than I would like to admit. Quirky place, with a very-diverse and idiosyncratically-organized inventory amongst which they have someone who will help you find (actually will themselves find because you couldn't find) what you need, whether it's a 30-year-old toilet fill valve or a weird-dimensioned commercial HVAC filter. And at 2:30 a.m. on a Sunday, when you are willing to pay just about anything for the part you need, it's the same as the price would be during the day.
     
  11. wjcandee

    wjcandee Wise One

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    That's a good observation!

    As to the replacement pilot seat, they don't sell it separately. The only 528 Valve part that they really sell separately is the R528 cap. But I would bet that if you called them and asked, they would find and send you a float assembly for free. They will actually let you talk to an engineer if the super-knowledgeable customer service folks there at the factory in Wisconsin don't know an answer, and they go out of their way to make you satisfied. That they do that regarding a $10 product is pretty-amazing and supports their reputation for actually caring about their customers.
     
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